A simplified design for ultra-sensitive X-ray detectors offering more precise materials analysis has been demonstrated at the National Institute of Standards and Technology (NIST). The advance is a step toward making such devices cheaper and easier to produce. Users may eventually include the semiconductor industry, which needs better X-ray detectors to identify and distinguish between nanoscale contaminant particles on silicon wafers.
The new design, described in the Sept. 13 issue of Applied Physics Letters,* is among the latest advances in a decade of NIST research on superconducting "transition edge" sensors (TES). These cryogenic sensors absorb individual X-rays, and then measure the energy of the X-ray by measuring the resulting rise in temperature. The temperature is measured with a bilayer of normal metal and superconducting metal that changes from zero resistance (superconducting) to a slight resistance level in response to the heat from the radiation. By measuring the X-ray energy, NIST researchers can identify the X-ray "fingerprints" of particular elements.
NIST researchers have built systems offering 30 times better X-ray energy resolution than detectors now used in the semiconductor industry and are pursuing further improvements such as novel detector geometries and materials. In contrast to the usual bilayer TES design, the sensor described in the APL paper combines the normal and superconducting metals into one homogenous layer. Manganese impurities are added to a 400-nanometer-thick aluminum film to lower its superconducting transition temperature to 100 milliKelvin. Fabrication requires about half as many steps as the bilayer design. In addition, the new design exhibits less "noise" in the X-ray signals than is typical for TES sensors, as well as a low sensitivity to magnetic fields that could help in building stable instruments.
Laura Ost | EurekAlert!
Mars 2020 mission to use smart methods to seek signs of past life
17.08.2017 | Goldschmidt Conference
Gold shines through properties of nano biosensors
17.08.2017 | American Institute of Physics
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy